The invention relates to a hill start assistance method for a motor vehicle.
The invention also relates to a hill start assistance device for the motor vehicle, associated with the method.
The invention further relates to a vehicle comprising such a device.
In a hill start, and in the absence of any assistance solution, the driver may be caught out by the backward movement of the vehicle.
Manufacturers have therefore proposed solutions aiming to remedy this drawback.
These solutions are based on various techniques. Of these, some are based on determining the clutch torque to hold the vehicle immobile, based on the knowledge of the engine torque.
It is possible, for example, to cite the document DE 102 421 22 (D1) in which it is proposed to keep the brake of the vehicle active for a predetermined duration in order to facilitate the driver's hill-start maneuver, the brake being released if certain conditions are satisfied, and, among other things, if the clutch torque exceeds a minimum threshold corresponding to the immobility of the vehicle on the gradient.
However, the clutch torque is estimated in such a way in D1 that the torque applied to the drive wheels, via the transmission, may be situated below the threshold needed to ensure a safe hill start, that is to say one that does not in particular generate any backward movement of the vehicle.